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When to Plant Rosemary in Montezuma County, CO

Montezuma County, Colorado Zone 7a May

Top priorities for Montezuma County, Colorado gardeners in May

Your Montezuma County, Colorado garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost May 27
Avg. first frost September 27
Soil temp (4") 34°F
Watering High
Pest pressure Low
Daylight 14 hrs
Looking ahead to June
  • Transplants going out: rosemary

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Rosemary is an aromatic evergreen shrub with needle-like leaves and a piney, citrus flavor. It is a Mediterranean herb that thrives in warm, dry conditions.

Montezuma County, Colorado is in USDA Zone 7a. The average last spring frost is May 27 and the first fall frost is September 27, giving you a growing season of approximately 123 days.

At an elevation of 8,063 feet, Montezuma County receives approximately 15.2 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Rosemary to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Rosemary successfully. Mulch heavily to conserve soil moisture.

Montezuma County, CO (Zone 7a) Short season
123 days
Last Spring Frost May 27
123 growing days
First Fall Frost September 27
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Montezuma County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (259 days to spare)
Transplant: May 26 🍅 Harvest: Aug 18 – Jan 5
Recommended (50%) ✓ Fits season (257 days to spare)
Transplant: Jun 3 🍅 Harvest: Aug 26 – Jan 13
Safe Start (90%) ✓ Fits season (256 days to spare)
Transplant: Jun 20 🍅 Harvest: Sep 12 – Jan 30

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Soil Compatibility in Montezuma County

How your county's soil matches Rosemary's growing requirements.

Soil pH

Your soil pH (6.4–7.7) overlaps with Rosemary's range (6.0–7.5), though not a perfect match.

Soil Texture

The loam soil in Montezuma County is excellent for Rosemary — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.8%). Annual compost additions will help Rosemary.

How to Plant Rosemary

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Plant Water Budget

Plant needs
0.3″/week
Rainfall provides
0.5″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Rosemary

Rosemary needs approximately 0.3 inches of water per week (1.3" per month). Here's how your county's rainfall compares month by month.

Month Rosemary Needs Rainfall You Supplement Action
Jan 1.1" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 1.3" 0" ❄️ Dormant
Apr 1.7" 0" ❄️ Dormant
May 1.3" 1.8" 0" ✅ Rainfall sufficient
Jun 1.3" 1.1" 0.2" 💧 Light watering
Jul 1.3" 1.3" 0" ✅ Rainfall sufficient
Aug 1.3" 1.6" 0" ✅ Rainfall sufficient
Sep 1.3" 1.3" 0" ✅ Rainfall sufficient
Oct 1.5" 0" ❄️ Dormant
Nov 1.1" 0" ❄️ Dormant
Dec 0.9" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Montezuma County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Rosemary Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Rosemary needs ~1,690 GDD — county provides 1,599 GDD Tight fit

Rosemary Planting Timeline — Montezuma County, CO

Rosemary Planting Calendar

Activity When Date Range
Transplant Outdoors June 3 Jun 3 – Jun 17
Harvest August 26 Aug 26 – Jan 13

Plant 0.5" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January Harvest
February
March
April
May
June Transplant Outdoors
July
August Harvest
September Harvest
October Harvest
November Harvest
December Harvest
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.3"/week · Natural rainfall sufficient

📅 Days to Maturity

80–180 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

123 days in Montezuma County

Growing Tips for Rosemary in Montezuma County

Direct sow Rosemary outdoors after May 27 in Montezuma County when soil has warmed and frost danger has passed.

Your 123.0-day growing season in Montezuma County is tight for Rosemary (80.0-180.0 days to maturity). Start indoors and choose early-maturing varieties.

General growing tips

Grow in well-drained soil and avoid overwatering. In cold climates, grow in containers and bring indoors for winter. Propagate from stem cuttings for faster results than seed.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Rosemary in Montezuma County, CO?

Montezuma County is in Zone 7a with an average last frost of May 27. Plan your Rosemary planting based on this frost date — see the calendar above for exact timing.

What planting zone is Montezuma County, CO?

Montezuma County, Colorado is in USDA Hardiness Zone 7a. The average last spring frost is May 27 and first fall frost is September 27.

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Your Montezuma County Garden Planner — Free

A 24-page printable planner built for Montezuma County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Montezuma County, CO. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.